The Whirlpool AP51030K features a three-stage purification system made up of a pre-filter, carbon filter, and true HEPA filter. The air purifier's outdoors grill functions as an irreversible pre-filter by catching big particles and preventing them from getting in the system. Huge particles that find their method inside the system are immediately captured by the carbon filter, which likewise works to eliminate unwanted smells and protect the life of the HEPA filter. At the heart of the Whirlpool Whispure 510 is true HEPA purification. HEPA filters supply optimal purification of your space's air by getting rid of approximately 99.97 % of particles that are 0.3 microns and larger. These particles include family pet dander, allergen, pollen, ragweed, mold spores, and other microscopic irritants that can harm your indoor air quality and worsen allergy and asthma symptoms.